Method of refining glyceride-type oils



Feb; 13, 1940. a. CLAYTON l 4 2,190,589

METHODvOF REFINING GIYGERIDE-TYPE OILS Filed Jan. 4, 1937 2 Sheets-Sheet' 2 3" 56 TTOR/VEK VPatented Feu-13, 1940 l l 2,190,589

UNITED STATES PATENT oFFlci-z Bcnamin Clayton, Sugarland, Tex., assgnor to Refining, Inc., Reno, Nev., a corporation of Nevada f Application january 4, 19am-serial Nn. 119,023

13 claims. (ci. 26o-426) My invention relates to a novel method and terially saponiiication f neutral oil and reduce apparatus for refining glyceride-type oils, and the amount .of oil in the soapstock without inhas among its objects the lowering of rening creasing the color of the rened oil, even often losses without increasing the color ofthe refined producing an oil of better color, by proper use oil, in many instances producing an oil of better of a third material. This material is an agent vl5 color. i which acts, in the quantities used, as a de-emul- A crude glyceride-type oil contains free fatty sifying agent and as an inhibitor for saponiflcaacids and other impurities. For example, crude tion of neutral oil, being hereinafter termed a cottonseed oil may contain free fatty acids rangde-emulsifying and inhibiting agent. It is ing in quantity from a fraction of one percent preferably volatile and has a tendency to break 10 to more than two percent. It is common pracor prevent the formation of the usual uniformlytice to refine such glyceride-type oilsby use of emulsified character of the soapstock. Its power an alkali refining agent, usually in dilute aqueto inhibit the saponification of neutral oil is of ous solution, such as .caustic soda or caustic particular importance as it reduces this saponilo potash. These and other rening'agents capable fication loss one-half or more. It may desirably l5' of reacting with the impurities to form foots and be of such character as in effect to grain out thus refining the oil are herein included in the color impurities.'

term refining reagent. l Onlysufilcient quantity of this agent is used While such refining reagents have apreferto inhibit saponification of neutral oil 4by the entialaflinity for the free fatty acids, they also excess of the refining reagent employed, and to 20 tend to react with the oil itself. 'The loss in exert the desired de-emulsifying action. This volume of a crude glyceride-type oil during such quantity is preferably small, seldom exceeding refining is called the refining loss.l It is made more than a few percent and usually .being beup partly of the loss due to the formation of tween .75% and 1.7% based on the weight of the foots from the free fatty acids and other imoil, though these limits are not invariable and purities initially in the oil, a necessary loss, and `may be departed from, being here setiorth by partlyof the loss due to the action of the rea way of illustration. With exceptional oils congent on the oil itself and due to entrainment of taining large amounts of fatty acids, for examoil in the separated foots, a loss which is very ple, above 3%, it maybe necessary to increase materially' decreased in the present invention. somewhat proportionally the quantity of the de- $0 It is almost invariably the practice to, add a. emulsifying and inhibiting agent. It is further greater quantity of the refining reagent than is desirable that such small quantity be used as theoretically necessary to neutralize the free not to interfere with satisfactory separation of fatty acids, the excess acting to produce a proper the rened oil from the resulting soapstock.

y bleach by removing objectionable color. How- The alcohols have been foundvery satlsfac- $5 i.

ever, in conventional batch treatment this extory as such a third agent, though'various other cess tends to saponify a portion of the neutral chemical agents may be used. Monohydric or oil, thus increasing the refining loss. polyhydric alcohols may be used, but the former In reacting with the impurities, the refining are preferred. For example, butyl, iso-propyl,

Vare composed primarily of soap and various give satisfactory resul ,those most miscible with -color impurities and are in the form of minute water being preferred, for example, iso-propyl particles which tend 'to settle if allowed to stand,y or ethyl. Iso-propyl alcoholhas been found to quiescent. Oil may be associated therewith either be particularly advantageous.I The term alcoby being emulsined within the particles, or by ,ho hereinafter used represents one example of 46 being entrained in the voids between such para de-emulsifying agent and includes alcohols of ticles. Usually both types of association may the monohydric or polyhydric types, or mixtures coexist, especially if gravitational separation is thereof. utilized. In-a continuous-refining system uti- Various chemical lagents other than alcohol v lizing a centrifuge for separating the oil and the can also be used as the de-emulsifying and in- I0 footsy it is possible to recover most of the oil in. hibiting agent.4 Various of the esters can ,also these voids, but the present invention goes even be employed, for example, ethylacetate, or the further in seeking to eliminate in addition losses, renning reagent may comprise sodium alcoholate, due to the emulsifled oil. potassium alcoholate, etc. K 55.. .I have found it possible to decrease very ma- -The de-emulsifying and inhibiting agent may reagent forms foots or soapstock. 'I'hese foots propyl, amyl, ethyl or other monohydric alcohols 40 be added by mixing with-the rening reagent, or it may beqadded to' the oil before or after addition of this refining reagent. The rstmentioned system is preferred, the resulting rening solution usually containing from 10 to of the alcohol, or other de-emulsifying and inhibiting agent, though these limits can often be departed from. For instance, with grain alcohol it is possible to use even more alcohol than water in the solution. With iso-propyl alcohol it is usually desirable that the solution of alcohol and refining reagent contain not more than 15% thereof, though slightly more and up to 25% can be used.

It is an object of the present invention to reduce saponification of neutral oil in a batch or continuous process for refining glyceride-type oils, and to produce other desirable results in such a process.

It is another object of the present invention to refine glyceride-type oils by use of a refining reagent and an agent inhibiting saponification of neutral oil and acting as a de-emulsifyingagent to reduce the amount of oil in the soap-stock.

It is a further object of the invention to add and subsequently remove this de-emulsifying and inhibiting agent in such a process.

While batch operation of the invention is quite successful, I have found particularly good results and excellent economies in operating in a continuous manner. experienced during batch treatment in uniformly mixing alcohol, for instance, with a large body of oil can be overcome in a continuous process by mixing small quantities of the three materials, preferably by continuously mixing suitably proportioned streams thereof. If this mixing is done in a confined space there is no loss due to l moved from the mixing zone as fast as it is evaporation, and other very desirable ends are accomplished. The mixing action can be made very complete and the resulting mixture can be formed.

It is an object of the present invention to add to one portion of a continuous refining system a de-emulslfying and inhibiting agent and to remove this agent at another portion of the system.

Another object is to mix small quantities of the materials, preferably by mixing proportioned streams thereof.

Another object of the invention is to move the resulting mixture from the mixing zone as fast as produced, preferably as a stream moving with such flow conditions that stratification or separation of the materials is prevented, thus insuring delivery of a uniform mixture to the separating means.

A proper excess of the refining reagent is preferable in the process over and above the amount theoretically required to combine with the free fatty acids, the excess being that customarily used and acting on the color impurities. 'I'he removalcf such color impurities is a function of time, and While With certain oils this reaction is very rapid, some oils require a longer time of l contact with this excess refining reagent. Heat may accelerate this color-removing reaction and facilitate later separation of the mixture. In

the present invention flow of the mixture through an elongated zone will give this additional time, if required, and heat may be applied during this flow if desired.

It is an object of the present invention to 'mix a glyceride-type oil, a refining reagent and a deemulsifying and inhibiting agent and condition Any difficulty which may be the resulting mixture during ow through a passage before separating any of the materials in the mixture from the remaining materials thereof.

. these products can be separated in various sequence. The resulting reaction -products can be so treated asl to rst remove the de-emulsifying and inhibiting agent, for instance by vaporization, leaving a mixture of refined oil and foots vwhich is later separated. On the other hand, the

system herein described in detail first separates the refined oil from the resulting reaction prod-- ucts, subsequently separating the foots and the de-emulsifyingand inhibiting agent.

It is an object of the present invention to separate the refined oil, foots, and de-emulsifying and inhibiting agent, regardless of the sequence of separation, and regardless of the expedients utilized to effect this separation, whether by vaporization, centrifugal action, gravitational action, filtration, etc.

Another object of the invention is to add a` vaporizable agent to'one portion of a refining system, then separate refined oil from the reaction products, and subsequently vaporize` this agent from the foots.

While it is quite possible by use of the invention to ref-lne some oils without use of temperatures above room temperature, refining is usually better at somewhat elevated temperatures. For instance, it is often possible to preheat the oil to a desired degree, and, if desired, the refining reagent and the de-emulsifying and inhibiting materials can be heated before separation. If centrifugal separation is used, it is often desirable to heat the zone where this centrifugal force conditions, either refining the oil in the cold, or

applyingv heat at one or more positions in the system.

Another object of the invention is to provide a refining process capable of partially or completely dehydrating the foots by vaporization of Water therefrom, if this expedient is desired.

In the preferred embodiment of the invention the dehydration of the foots may be accomplished under relatively'high temperatures, and under pressure, if desired. I have found that if a mixture of foots and water, or a mixture of foots, .water anda de-emulsifying and inhibiting agent, is subjected to temperatures from 212 to 600 F., the resulting dehydrated foots will have distinctly unexpected properties. Such treatment produces soapstock (foots) which is not of the odoriferous character produced by' present processes. The high temperatures utilized apparently break` down the odoriferous substances, usually proteins, into non-odoriferous products which are unobjectionable in the dehydrated.

soapstock. The resulting product' can be used lfrom conventional soapstocks.

The resulting soapstock will not ferment over lagent. In other instances, the mixture of these long periods of time. Soapstock produced by conventional methods will ferment and necessitate shipping in steel tank cars. The improved product of the present invention can be shipped in any kind of container such as paper packages, wooden barrels, or loose in box cars, and will not ferment. It occupies less space and can be shipped in dust or powdered form. Its anhydrous character makes shipping quite economical as compared with ordinary soapstock which contains about 50% of4 water.

It is an object ofthe present invention to produce a dehydrated soapstock by .subjection of the foots, usually associated with water or with water and a de-emulsifying and inhibiting agent, to a temperature suflicient to convert the odoriferous substances into non-odoriferous products,A

this temperature usually being between 212 and `600 F., and preferably between 300 and 600 F.

The superior product can be obtained regardless of whether or not a de-emulsifying and inhibiting agent is present during such heating. In some instances, all or a portion of the water may be removed before subjection to high temperatures to convert the odoriferous substances, the provision of such a method being also Within the objects of the present invention.

The new soapstock product is also a part of the present invention, being believed to be novel g per se. Y

In some instances, the refining is made better by preliminarily treating the crude glyceridetype oil to remove gums and mucilaginous matter therefrom before the refining reagent acts upon the free fatty acids and other impurities to form the foots. It is an object of the present invention to preliminarily treat the incoming oil, if desired, to remove gums and mucilaginous matter therefrom. 'I'his often assists separation and further improves the color of the refined oil.

Further objects and advantages of the invention will be made evident hereinafter.

T he drawings. illustrate vseveral embodiments of the invention. Referring particularly thereto:

Fig. 1 represents'a pipe line diagram of a refining system incorporating the features of the invention;

Fig. 2 is a fragmentary view of an alternative system for separating substance;

Fig. 3 isl a section taken on the' line 3-3 of- Fig. 2:

Fig. 4 is a fragmentary view of another alternative system for separating the foots from the liquid substance; Fig. 5 is a section taken on the line 5--5 of Fig. 4; 'l

Fig. 6 is a fragmentary view diagrammatically illustrating a system in which vaporization of the de-emulsifying and inhibiting agent may take place in .part in the centrifuge.

Fig. 1 diagrammatically shows a complete system capable of preliminarily-treating the oil to remove gums and mucilaginous matter preparatory to refining. The particular degumming system diagrammatically -shown in Fig. 1 is very satisfactory in this regard but is not per se a part of the present invention, being claimed in the copending application of Benjamin H. Thurman, Serial No. 6,446 entitled Method of treating vegetable oils and product obtained thereby. Various systems, eithen batch or continuous',may be used in this capacity, though the continuous system shown is particularly desirable in con- `junction with the subsequent refining equipment.

the foots from the liquid erence to continuous operation,

As shown in Fig. 1, the crude glyceride-type oil may be supplied to a tank I, usually after preliminary filtration to remove' fibrous materials or solids.` The de-gumming reagent in tank 2 may comprise water, alcohol, or any electrolyte such as dilute aqueous solutions of acids, alkalis, or salts. A ten percent borio acid solution gives excellent results. if used, is designed to remove gums and mucilaginous matter, not to react with the free fatty acids of the oil.

A pump 3 may continuously withdraw oil from the tank I, delivering a stream thereof to pipe 4. A pump 5 may deliver a proportioned quantity connected to the pump 3 by a variable speed mechanism 5a. These materials` are intimately.

This preliminary treatment,

mixed together by any suitable mixing means,

injection of one liquid intoa stream of another having been found entirely satisfactory in this regard. The quantity of de-gumming reagent ispreferably from 1 .to l0 percent of the oil, by volume, though larger quantites of the de-gumming reagent may be used.

The mixture is heated in a heater 6 shown as including a coil 1, positioned in a container through which a s 'table heating medium is circulated, the temperature being raised to a degree facilitating centrifugal separation when the mixture is introduced into a centrifuge 8. Here the reaction products are separated into de-gummed oil, delivered through a spout 9, and a material containing the gums, mucilaginous matter and other impurities of similar character. The degummed -oil enters atank I0 and may be withdrawn therefrom at a rate corresponding to the rate of introduction. It will be clear, however, that if this preliminary treatment is not desired. the n crude glyceride-type oil can be moved directly into the tank I0.

A tank II may contain a body of the refining reagent, and the alcohol or other cle-emulsifying and inhibiting agent may be retained by a tank I2. .If desired, any or all of these three materials may be preliminarily heated intheir respective tanks or may be heated in pre-heaters Ilia, IIa, and I2a, before being mixed. Such preliminary heating is not necessarily used but offers one valuable way of controlling the temperature conditions in the system.` If heat is applied to one or more of the three materials before mixing, particularly to theoil, it will facilitate pumping and may be used to increase the effectiveness of the later steps in the process.

By way of illustration, and for exemplary purpose only, the process will be described with refand with reference to alcohol as the de-emulsifying and inhibiting agent, the rening reagent being an aqueous alkali solution.

In a continuous process, it is desirable to mix the three materials in proportioned quantities in a confined space closed from the atmosphere. Preferably only small quantities of the materials are mixed at a time, andV the mixture is preferably maintained with such flow conditions-that the ingredients of the resulting mixture remain uniformly mixed `to prevent premature separation. These ends are best accomplished by mixing proportioned streams containing these materials. For example, proportioning pumps I3, Il and I5 may respectively draw these materials from the tanks I0, Il and I2, these materials moving through the `pre-heaters, if desired. 4These vcomprise the forward part of a confined space defined in part by a pipe into which the pump I3 may directly discharge.

Satisfactory mixing of the three materials can be obtained by suitable introduction of the alkali solution and the alcohol into the pipe 20, either separately or combined to form a rening solution. For instance, the pumps I4 and I5 may separately supply the alkali solution and the alcohol to the 'pipe 20 through pipes 22 and 23, the -alcohol being supplied either upstream or downstream from the point of introduction of the alkali solution. On the other hand, it is often desirable to preliminarily mix the alkali solution and the alcohol Ito form a refining solution which is then introduced into the oil. This may be accomplished by closing a valve 24 in the pipe 23, and opening a valve so that the pumps I4 and I5 discharge into the pipe 22, the resulting refining solution being then introduced into 'the pipe 20 to mix with the oil. In other instances, the alkali solution and theialcohol can be preliminarily mixed in the tank II, the resulting refining solution being pumped through the pipe 22 into the pipe 20 in proportioned quantity.

Various auxiliary mixing devices such as a mechanical mixer can be used if desired, but a satisfactory mixing can be obtained by injectionof one material into the stream of another. This minut-ely dispersos the alkali and the alcohol in the oil, forming an excellent mixture and permitting the alkali to act very rapidly on the free fatty acids of the oil so that the resulting foots will be formed while the alcohol is present or immediately preceding the point of introduction of this alcohol. yThe resulting mixture will include oil, foots, water, alcohol, and any excess ofthe alkali over and above the amount theoretically necessary to combine with the free fatty acids, this excess acting upon the color impurities during continued flow through the pipe 20. By pumping the materials into such a confined space, the resulting mixture will move fromthe mixing zone as fast as it is formed. It is preferable to maintain such ow conditionsin the confined space that stratification or premature separation of any of the ingredients is prevented.

Flow along a confined space such as is defined by the pipe 20 will give this desirable action, and

will condition the mixture preparatory to sepa.-

ration. One phase of this conditioning involves action of the excess alkali on the color. impurities. With ysome oils, this reaction is very rapid in which event the confined space need not be necessarily long to give the desired reaction time. With other oils, a more prolonged time of contact is desirable, and a'correspondingly longer confined space is desirable, thus increasing the reaction time before separation.

It is sometimes desirable to heat this resulting mixture during flow through such a confined space. In this capacity I have shownA a coil 26 of a heater 21 as forming a part of the confined space, heat being supplied by any suitable means such as a burner 30. Other types of heaters providing a confined space closed from the atmosphare maybe utilized, though in some instances no heat need be applied at this point. Flow therethrough should. preferably maintain the uniformity of the mixture in the sense that stratification or premature separation is prevented, thus insuring delivery to a separating means of a mixture which does not vary from time to time in composition.

In the system shown, the resulting products are iirst treated in a manner to separate the refined oil. The separation is preferably continuous and Fig. 1 illustrates a centrifuge 3I acting in this capacity. Conventional high-speed centrifuges can be used to separate the resulting products into refined oil and a liquid substance containing the foots, water, and the de-emulsifying and inhibiting agent, in this example alcohol. Thus, refined oil may be continuously discharged through a spout 32, and the liquid substance delivered through a spout 3`3 to a tank 34. Preferably such centrifuges will be substantially closed from the atmosphere to prevent loss of alcohol. However, superior separation, lower refining losses, and continuous operation over long periods of time can be effected by utilizing a heated centrifuge such as is disclosed `in the application of Benjamin Clayton, filed August 1, 1935, Serial No. 34,258, now Patent No. 2,100,277, granted Nov. 23, 1937. For instance, a heating medium such as' steam may be supplied through a pipe 35 to the exterior of the rotating bowl of the centrifuge.

Refining of some oils can be accomplished by use of little or no excess temperature. For instance, the materials can be mixed at substantially room temperature and moved to the centrifuge 3| Without intermediate heating, especially if the centrifuge is of the heated type. In most instances, however, superiorresults are obtained by pre-heating one or more of the incoming materials, or applying heat to the resulting mixture, or by using both of these expedients. Even then, however, better results will be obtained by use of a heated centrifuge. 'Ihe desirable temperature of the resulting products issuing from the coil 26 will depend in part upon the type of separating means utilized and upon the character of the oil. If a centrifuge is used, very satisfactory results can be obtained by introducing the resulting products thereinto while at a temperature between and 180 F. However, these temperature limits are not invariable, and temperatures somewhat above orv below this range can often be used with success, depending upon the oil being refined, the type of centrifuge utilized, etc. A temperature between and 140 F. is usually suilicient especially if a heated centrifuge is used. For example, the mixed products may go to theheated centrifuge at F., the refined oil discharging therefrom at substantially the same temperature and the liquid sub-l liquid substance and from the foots by various expedients. Vaporization ispreferred, and three alternatives are indicated in Figs. 1, 2 and 4.

In Fig. 1 this -liquid substance is continuously withdrawn from the tank 34 by a pump36 orl by a vacuum in the subsequent equipment. If desired, it may move through a heater 31 preparatory to introduction into a vaporizing chamber 38 defined by a container 39. It is preferable that this heat be supplied during flow through a confined space such as is provided by the coil 40 shown. Heat may be supplied by a suitable burner or by a hot medium circulated exterior of such a coil. Sometimes very little, if any,

heat need be applied at this point, and it is oftenY possible to dispense with the heater 31, moving the liquid substance directly into the chamber 38. However, the temperature of the .liquid substance prior to reaching the chamber 38, or after it reaches this chamber, should be such that the de-emulsifying and inhibiting agent, in this instance alcohol, will assume a vapor state when subjected to the low pressure maintained in this vaporizing chamber 38. This heat may be supplied by the heater '31, by circulating a hot medium through a jacket 4l around the container 39, or by injecting a hot medium such as steam into the chamber 38. If desired, the flow ofthe liquid substance into the chamber 38 may be throttled as by a nozzle 42 or a valve 43. Thus,

pressures above atmospheric can be developed in v the coil 48 if desired.

In this embodiment it is preferable to remove all of the alcohol by vaporization at this stage of the process. By proper control of temperature and pressure conditions it is also possible to remove all or apart of the water at this stage in the process, thus dehydrating the foots either partially or completely. By way of example, the system can be operated so that the liquid substance 'discharged from the centrifuge is at a temperature of about 160F. If supplied at this temperature to the vaporizing zone 38 maintained under a sufcient vacuum, all of the alcohol and a part of the water will vaporize. If further heated in the heater 31, or by the jacket 4I, or by supplying a heating medium -to the chamber 38, all of the water can be vaporized and removed along with the alcohol vapors. s

The resulting vapors may be forcibly withdrawn through a pipe 44 by use of a vacuum pump 45. If vapors of both water and alcohol are withdrawn they may be fractionally condensed or condensed together and later separated by any means well known in the art of separating such materials. Fractional condensationis illustrated in Fig. 1, the water being condensed in a condenser 46 and dropping through a barometric column 41 to a tank 48, the alcoholv vapors moving through a pipe 49 and being condensed in an alcohol condenser 58, the condensate moving downward in a barometric column I. to a tank 52. These condensers may be of the tube type,

` the tubes being surrounded by a circulating cooling medium.` The lower ends of the barometric columns may be submerged, and these columns are of sufficient height to balance the low pressure developed by the vacuum pump 45.

The alcohol can be recovered almost entirely and is preferably re-used in the system. A pump 53 may withdraw this alcohol from'l the tank 52 and deliver it to the tank I2. Similarly, the water may be re-used, being withdrawn from the tank 48 by a pump 54 discharging into a mixing tank 55. Here the reining reagent may be prepared, as` by mixing alkali therewith, this alkali being delivered through a pipe 56. The resulting alkali solution is moved by a pump 51 into the tank Il.

The foots which remain after vaporization of the alcohol are preferably withdrawn continuously from the chamber 38 byany'suitable pumping means capable of withdrawing these foots without impairing the vacuum in this chamber. Fig. 1 discloses a screw conveyor acting in this capacity. This conveyor may provide a housing 68 opening on thev chamber 38, and a screw 8| rotating therein under the influence of a drive means 62. `The foots are thus advanced leftward inside the housing 68 and the pressure progressively increases therein until suiiicient pressure is developed to extrude the foots through an extrusion means 83. This conveyor may thus act as a pump, intaking at the low pressure maintained in the chamber 38 and developing a suiiicient pressure to extrude the foots. It acts as a vacuum seal and withdraws the foots without impairing the low pressure in the chamber 38. The screw 68 is preferably formed in flights, with stationary members the housing 68 between these flights to better insure continuous movement of the foots.

It is often desirable to subject the foot-s or soapstock to high temperatures to produce the improved product hereinbefore mentioned. In'

64 extending inward from- Fig. l, this can be accomplished by applying suf cient heat either in the heater 31 or in the chamber 38, preferably the former. Thus, sulicient heat can be supplied in the coil 48 over and above that required to vaporize the alcohol. The liquid substance can be raised to a temperature between 212 and 600 F. to convert the odoriferous substances in the soapstock into nonodoriferous products. Most satisfactory operation is obtained by -use of temperatures between 300 and 600 F. if this product is to be obtained, though the temperature will vary with diierent soapstocks.. Even higher temperatures can be utilized in some instances without departing from the spirit of the invention, it being clear that there` is no possibility of injuring the refined oil, for this oil has previously been separated. This heating may be carried out under pressure by partially closing the vave 43 or properly designing the nozzle 42. However, necessary.

If this non-odoriferous soapstock is to be produced by use of high temperatures it is often possible to dispense with the use of any high vacuum in the chamber 38, for the heat applied before or after reaching this chamber .may be sufficient to vaporize the alcohol and substantially all of the water even in the absence of a high vacuum.

On the other hand,'in making this non-odoriferous soapstock itis sometimes desirable to first extract the water and subsequentlyfheat the soapstock to theI temperature which will convert the odori'ferous substances. For instance, it-is possible to use temperatures in the coil 48 or in the chamber 38 only suicient to remove the alcohol and most o f the water, preferably using a high vacuum in this chamber. The resulting dehydrated soapstock may later be subjected to higher temperatures. For instance, it can be heated during the movement through the conveyor housing `68 by applying hot products of combustion to the exterior of this housing, or by circulating a hot medium through a jacket therearound. In any of the alternatives hereinbefore mentioned.

this is not absolutely the soapstock can be cooled before exposure to the atmosphere, if desired.

It will be clear that the production of this non-odorlferous soapstock is not essential to that concept of the invention relating to the use of a de-emulsifying and inhibiting agent in conjunction with the refining of the oil. If soapstock of this character is not desired, it is entirely possible to use lower temperatures in removing the water and alcohol, for instance. In such case, it is often possible to dispense with all heating immediately before or after the liquid substance enters the chamber 36. On the other hand, if this non-odoriferous soapstock is to be produced it will be clear that use of a de-emulsifying and inhibiting agent such as alcohol is not absolutely essential in the refining step. While a very desirable product of non-odoriferous character can be thus obtained, soapstock derived from other refining systems not necessarily using a de-emulsifying and inhibiting agent can be rendered nonodoriferous by subjection to the temperatures above mentioned.

Fig. 2 shows a system in which the alcohol or other de-emulsifying and inhibiting agent, and if desired, all or a portion of the water, may be vaporized during flow of the liquid substance through a conveyor.` Here, the liquid substance ows from the tank 34, or alternatively direct fromvthe centrifuge, through a valve 80 and enters a conveyor housing 8| in `which a screw 82 rotates. The entrance portion of the conveyor housing is surrounded by a jacket 84 through which a suitable heating medium is circulated to raise the temperature of the liquid, if not already high enough, to such an extent that the alcohol or other de-emulsifying and inhibiting agent is vaporized as well as any desired portion of the water if desired.

'I'he vapors can be removed through amanifold 85, being discharged into a condenser means shown as including condensers 06 and 81 similar to the condensers 46 and 50, previously described.

While vaporization at atmospheric pressure may be used, it is often desirable to decrease the .pressure in the entrance end of the conveyor housing to permit removal of the vapors' at lower temperature. For instance, a vacuum pump 90 may be connected to the condenser 81 to lower the pressure veyor housing The material entering the conveyor housing through the valve 80 is a liquid. As the alcoholV is vaporized the foots remaining in the advancing streaml becomen thicker. If sufficient heat is supplied to vaporize the water in whole or in part, as well as the alcohol, these footsI will be partially or completely dehydrated and will assume the form of a compacted mass which is moved leftward by the conveyor and extruded through an orifice 9| thus sealing the vacuum. Thus, regardless of water is vaporized, the surface of the material in the conveyor housing may be approximately as indicated by the dotted line 93, only the lefthand end of the conveyor being completely. filled with the foots.

In Fig. 4 another alternative is shown. The liquid substance moves from the tank 34 through a heater |00 as controlled by a valve |0I, being delivered to a belt conveyor |02 positioned in a housing |03. The belt may be of the endless type extending around rollers |04 and |05, suitably driven. This belt may `be of the type which assumes a troughlike form in the space between the rolls to bettenretain the liquid substance delivered thereto by the heater |00.

The liquid substance may be further heated during the time it is being advanced by the belt |02. Fig. 4 illustrates by way of example a series of pipes |06 extending through the zone between in the entrance portion of the conwhether the the upper and lower portions of the belt, the heating medium being circulated therethrough to heat the liquid substance suiciently to drive off the alcohol or other de-ernulsifying agent in vapor form if it wasnot previously at such temperature. through a pipe |09 to condensers ||0 and similar to those previously described. If evaporation under low pressure is desired a vacuum pump ||4 may be connected to the condenser to maintain-a partial vacuum in the housing |03. Application of sufficient heat, or utilization of sufiiciently low pressure, or both, may be used to partially or completely dehydrate the foots during this forward movement, if desired.

The foots, either containing water or in substantially anhydrous form, are discharged from the belt |02 near the roller |05 and drop into a suitable pump capable of continuously withdrawing the foots without impairing any low pressure which may be used in the housing |03. A screw conveyor is shown in this capacity, providing a housing with a screw ||6 rotating therein. If low pressure is used in the housing |03, this conveyor will progressively increase the pressure on the foots, ultimately extruding these foots through an orifice 8.

Fig. 6 diagrammatically illustrates an alternative system which will also be described with reference to alcohol as the de-emulsifying and inhibiting agent. The first part of the system is the same as shown in Fig. 1, the reaction products flowing from the heater 21 through a pipe as controlled by a valve Vi5| moving toa centrifuge |52 which is maintained under a partial vacuum. Centrifuges of this in the art, and the refined oil can be forcibly withdrawn by a pump |53, the liquid substance containing foots, water and usually a portion of the alcohol, being continuously withdrawn through a pipev|55 provided with a valve |56.. The temperature of the incoming reaction products may be such that a portion of the alcohol will vaporize in the centrifuge |52, the vapors being withdrawn through a pipe |51 with branch pipes |58 and |59 respectively communicating with the upper and lower pans which collect the oil and the foots. These vapors may be condensed in a condenser |60, being drawn thereinto under the influence of a. vacuum pump |6I. 'Ihe condensate drops through a barometric column to a tank |62.

Liberation of vapors in the centrifuge is facilitated by supplying a heating medium through a pipe |64, the centrifuge being of the heated type previously mentioned.

If desired, substantially all of the alcohol can be removed at this stage of the process, though it is preferable to so operate the system that only a portion thereof separates at this point. 'Ihe remaining alcohol, and any desired portion of the water, can be removed by moving the liquid substance directly into a low-pressure zone |10, or preliminarily through a heater |1| corresponding to the heater 31 previously mentioned. A higher vacuum may be maintained in the chamber |10 than in the centrifuge |52, if desired. The remaining alcohol, and the water if desired, can4 be removed from this chamber |10 in vapor state to condensers |1| and |12 under the action of a vacuum pump |13.

The vapors move from the housing |03I type are known The foots either containing substantially all.

means of a conveyor IBD similar to the conveyors previously mentioned.

In conclusion, the following example will indicate the superior results obtainable by the use of a de-emulsifying and inhibiting agent used in conjunction with a refining reagent, considered with reference to production of a refined oil in the system shown in Fig. 1 and using a crude cottonseed oil, not previously de-gummed, and containing 1.4% free fatty acids. Using -no alcohol and 4.44% of 20 B. refining reagent there was a loss due to excess saponification of 3.37% the resulting refined oil having a color of 35 yellow, 6.0 red. When the same percentage of refining reagent was mixed with 1.1% iso-propyl alcohol to form a rening solution, and this was mixed withthis crude cottonseed oil, the excess saponification was reduced to 2.29%, effecting a saving of more than 1%. The color of the refined oil when using the alcohol was 35 yellow, 5.9 red. Other comparative runs show even better results anddefinitely establish the superiority of the present invention in inhibiting saponication-of neutral oil, reducing theamount of oil in the soapstock, and often producing better colorsevident either from the refined oil before bleaching or from this oil after washing, drying and bleaching'by conventional methods.

It will be understood that while the embodiments herein illustrated relate to a continuous process, this Inode `of operation is not essential. Batch operation is possible, the de-emulsifying and inhibiting'agent being added to the kettle', preferably closed and communicating lwith a con- -denser means for recovering this agent, for instance alcohl. The resulting mixture of refined oil, foots and the de-emulsifying and inhibiting agent can be separated in the kettle, the refined oil being separately withdrawn. The remaining liquid substance can be treated as hereinbefore described to separate the de-emulsifying and in. hibiting agent by vaporization thereof or by other expedients. n the other hand, the resulting mixture can be withdrawn from the kettle and the ingredients separated by various means and in various sequence.

I claim as' my invention:

1; A process of refining a glyceride-type oil,

which includes the steps of: continuously delivering to and mixing in a confined space proportioned streams of said glyceride-type oil, an alkali refining reagent capable -of saponifying neutral oil and of reacting with the impurities in said oil to form foots, and a small amount of a de-ernulsifying and inhibiting agent comprising a lower aliphatic alcohol added in such amount as to inhibit saponification of neutral oil by said rening reagent and yet act as a de-eniulsifler to prevent entrainment of oil in said foots; continuously moving the resulting mixture along said confined space; and separating the resulting reaction products while the same are in a heated condition into refined oil and foots containing said de-emulsifying and inhibiting agent, and 4vaporizing said agent from said foots.

2. A process of refining a glyceride-type oil, which includes the steps of; continuously delivering to and tioned streams of said glyceride-type oil, an alkali refining reagent capable of saponifying neutral oil andl of reacting with the impurities in said oil to form foots, and a small amount of a deemulsifying andinhibiting agent comprising a lower aliphatic alcohol added in Vsuch amount as to inhibit saponification of neutral oil by said remixing in a conned space proporfining reagent and yet act as a de-emulsier to prevent entrainment of oil in said foots; centrifugally separating the resulting mixed products whilethe same are ina heated condition'into refined oil and a liquid substance foots and said de-emulsifying and inhibiting agent; and vaporizing said de-emulsifying and.

inhibiting agent from said liquid substance.

3. A process of refining a glyceride-type oil, which includes the steps of: continuously deliver'-4 ing to and mixing in a confined space proportioned streamsof said glyceride-type oil, an alkali refining reagent capable of saponifying neutral oil and of reacting with the impurities in said oil to form foots, and a small amount of a deemulsifying and inhibiting agent comprising a lower aliphatic alcohol added in such amount as to inhibit saponication of neutral oil by said refining reagent and yet act as a de-emulsier to prevent entrainment of oil in said foots; continuously moving the resulting mixture along said confined space under such flow conditions that 'stratification is prevented thus maintaining a uniform mixture; and delivering this uniform mixture While in a heated condition to a centrifuge to' p separate refined oil therefrom.

kali refining reagent capable of saponifying neutral oil and of reacting with the impurities in said oil to form foots, and a'small amount `of a de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol added in such amount as to inhibit saponiflcation of neutral oil by said refining reagentV and yet act as a de-emulsifier to prevent entrainment of oil in said foots; continuously moving the resulting mixture along said confined space under such flow conditions that stratification is prevented thus maintaining a uniform mixture; centrifugally separating this uniform mixture while the same is in a heated condition into refined oil and a liquid substance containing said foots andc said ie-emulsifying and inhibiting agent; and vaporizing' said deemulsifying and inhibiting agent from said liquid substance.

'7. A method of refining glyceride-type oils which includes the steps ducing into and mixing in a confined space pro'- portioned streams of a glyceride-type oil and an alkali refining reagent capable of saponifying. neutral oil and of reacting with the impurities of said oil to form foots, one of said streams including a small amountof a de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol, the quantity of said refining reagent being in excess of that required to neutralize the free fatty acids of said oil; flowing the resulting mixture along said confined space to permit the excess refining reagent to act upon the color impurities of said oil and to condition said mixture for separation during the time. that said agent is present; discharging a stream of the resulting reaction products into a separating zone;

containing said of: continuously introseparating said reaction products in said separating zone while said products are in a heated containing foots and said de-emulsifying agent; and vaporizing said de-emulsifyng agent from said foots.

8. A method of refining glyceride-type oils which includes the steps of continuously introducing into and mixing in a confined space pro. portioned streams of a glyceride-type oil and an alkali refining reagent capable of saponifying neutral oil and of reacting with t e impurities of said oil to form foots, one of said streams including a small quantity of a de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol sufficient to inhibit saponication of neutral oil and to prevent entrainment of oil in said foots; flowing the resulting mixture along said confined space; 'centrifuging a stream of the resulting reaction products while the same are in a heated condition to separate refined oil therefrom leaving a liquid substance containing foots and said agent; and heating a stream of said liquid substance to vaporize said agent'therefrom.

9. A method o f refining glyceride-type oils which includes the steps of: continuously introducing into and mixing in a confined space proportioned streams of a glyceride-type oil and an alkali refining reagent capable of saponifying neutral oil and of reacting with the impurities of said oil to form foots, one of including a small amount of a lower aliphatic alcohol; flowing the resulting mixture along said confined space; centrifuging a stream of the resulting reaction products While the same are in a heated condition to separate refined oil therefrom leaving a liquid substance containing foots and alcohol; heating a stream of said liquid substance; introducing the heatedv stream into a chamber; and separately removing alcohol vapor and said foots from said chamber.

l0. A method of refining glyceride-type oils which includes the steps of: continuously introducing into and mixing in a confined space proportioned streams of a glyceride-type oil and an alkali refining reagent Icapable of saponifying neutral oil and of reacting with the impurities of said oil to form foots, one of said streams including a small amount of a vaporizable agent comprising a lower aliphatic alcohol, the quantity of said refining reagent being in excess of that required to neutralize thefree fatty acids of said oil; owing the resulting mixture` along said confined space to permit the excess refining reagent tol act upon the color impurities of said oil during the time ,that said vaporizable agent is present; resulting reaction products into a separating zone; continuously separating said .reaction products while the same are in a heated condition in said separating zone into rened oil anda liquid substance containing foots and said vaporizable agent; continuously withdrawing a stream of said liquid substance from said separating zone;

' introducing said stream of said liquid substance 2,190,589 condition into refined oil and a liquid substance l.

said streams.

discharging a stream of the' into a low-pressure zone to `separate said vaporizable agent from said foots; continuously with-l drawing the vapor of said agent from said lowpressure zone at such a rate as to maintain a subatmospheric pressure therein; and continuously removing the remaining foots from said low-pressure zone in a manner not to impair the low pressure in said zone.

1l. A method of refining glyceride-type oils which includes the steps of continuously introducing into and mixing in aconfined space proportioned streams of a glyceride-type oil and an alkali refining reagent capable of saponifying neutral oil and of reacting with the impurities of said oil to form foots, one of said streams including a small amount of a vaporizable agent comprising a lower aliphatic alcohol; separating refined oil from thel resulting reaction products while the same are in a heated condition to leave a liquid substance containing said foots and said vaporizable agent; flowing'said liquid substance as a stream; heating said stream of said liquid substance to remove said vaporizable agent in vapor form while ycontinuing the forward movement of said foots; and extruding said foots.

l2. A method of refining glycerid-type oils which includes the steps of: continuously mixing proportioned quantities of al glyceride-type oil, an aqueous alkali refining reagent capable of saponifying neutral oil and of reacting with the impurities of said oil to form foots in the presence of a small amount Aof a de-emulsifying and inhibiting agent comprising a lower aliphatic alcohol in such amount as to inhibit saponification of neutral oil and prevent entrainment of oil in said foots; separating the resultingreaction productswhile the same are in a heated condition into refined oil and a liquid substance containing said foots, water and said agent: and vaporizing said agent and at least a portion of said water from said liquid substance to at least partially dehydrate said foots.

13. A method of refining glyceride-type oils which includes the steps cf: continuously mixing proportioned quantities of a glyceride-type oil, an aqueous alkali refining reagent capable of saponifying neutral oil and of reacting with the impurities of said oil to form foots in the presence of a small amount of a vaporizable agent comprising a lower aliphatic alcohol; separating the resulting reaction products while the same are in a heated condition into refined oil and a liquid substance containing said foots, water and said agent; heating said liquid substance to a temperature between 212 and 600 F. to convert odoriferous materials in said foots into nonodoriferous materials; and separatingfrom said foots said water and said vaporizable agent in vapor state to leave dehydrated and substantially noni-odoriferous foots.

BENJAMIN CLAYTON. 

